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Commit 9b4231bf authored by Akinobu Mita's avatar Akinobu Mita Committed by Jens Axboe
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block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is huge 



SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls access a reserved
buffer in bytes as int type.  The value needs to be capped at the request
queue's max_sectors.  But integer overflow is not correctly handled in
the calculation when converting max_sectors from sectors to bytes.

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: linux-scsi@vger.kernel.org
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 63f26496

block/scsi_ioctl.c

+11 −4
Original line number Diff line number Diff line
@@ -82,9 +82,18 @@ static int sg_set_timeout(struct request_queue *q, int __user *p) 
	return err;

}



static int max_sectors_bytes(struct request_queue *q)

{

	unsigned int max_sectors = queue_max_sectors(q);



	max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);



	return max_sectors << 9;

}



static int sg_get_reserved_size(struct request_queue *q, int __user *p)

{

	unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9);

	int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));



	return put_user(val, p);

}
@@ -98,10 +107,8 @@ static int sg_set_reserved_size(struct request_queue *q, int __user *p) 


	if (size < 0)

		return -EINVAL;

	if (size > (queue_max_sectors(q) << 9))

		size = queue_max_sectors(q) << 9;



	q->sg_reserved_size = size;

	q->sg_reserved_size = min(size, max_sectors_bytes(q));

	return 0;

}